Comestibles such as cottage cheese, sour cream, cream cheese dips and the like are typically packaged in cup-like containers having closures or lids made of relatively resilient organopolymetric materials. Closures or lids for such container cups are depressed inwardly relative to the top of the lip and are relatively flexible in construction to provide for ease of handling by the consumer. Such lids, however, present difficulties when forces within the container expand the lip outwardly. In such circumstance they may cause breakage of the seal. Such lids typically provide a two point vacuum seal in cross-section between the lid and the cup. However, such lids loose vacuum as force is applied to pull the lid inwardly since the lowermost sealing point of the lid separates from the cup wall thereby allowing air into the container. Similarly, when lids are constructed to be suitable to maintain a vacuum seal, they are not suitable for maintaining a pressure seal. In the latter case, the forces operate in the opposite direction, i.e., away from the lid.
We have invented a sealing lid which avoids the aforementioned problems and permits bi-directional sealing for both pressure and vacuum forces.